Firstly, you should all get yourselves a copy of Baby Bargains. The newest edition is supposed to come out in April, with the most up to date reviews on pretty much EVERYTHING you need for your kid.
And as far as crib bedding goes. Those sets are really a waste. Don't get me wrong, they are fun to browse through and are great inspiration for nursery themes, but you are spending $100-200, if not more, on a lot of stuff you won't or shouldn't use.
Let's look at this top seller at BRU.http://www.toysrus.com/product/index.jsp?productId=3755957&fromWidget=BRU%3ACategory%3ATop+Sellers Adorable, right? What do you get for $200? A lightweight quilt (shouldn't have in the crib with a newborn, I think most people hang this on the wall or something), bumper (suffocation hazard, then a climbing hazard once the baby is older), dust ruffle (cute, sure, but who cares?), fitted sheet (you will want 5 of these), window valance (cute, sure, but who cares again?) and diaper stacker (I don't think anyone actually uses this thing. They might put diapers in it before the baby comes but that step probably gets cut out pretty quick).
Eventually you can use the blanket, sure, but by then you may want to move LO to a "big boy/girl" room and do a different theme, or move them up to a twin bed and it will be way too small. You're also going to get more blankets than you know what to do with because every other person who gives you something for the baby will probably include at least one blanket in their gift. A lot of those sets also sell a lot of accessories that aren't included in the sets (mobiles, lamps, thermal blankets, etc.), or you can buy the things in the sets separately (like the window valance or the fitted sheet) that you can use to keep with the theme if you want.
What you actually need for crib bedding: At least 1-2 mattress pads ($10-20$ each), at least 4-5 crib sheets ($10-$20 each, and they have plenty of solid colors and prints at BRU), a few lightweight blankets ($5-$25 each, square are easier to swaddle with than rectangular), sleepsacks (about $20 each, these are GREAT for little babies in the winter), and swaddling blankets/SwaddleMes ($10-$25 each). I'd personally recommend a breatheable bumper, too, and they come in an assortment of lighter colors. You may also want a "sheet saver" but I couldn't attach these properly on Sarah's crib. I don't think we ever had a middle of the night blow out so I didn't miss it, but I think I just got really lucky there (I honestly think I could count the number of times she's pooped during the night on one hand).